Wet-cloth brush for vacuum cleaner and a vacuum cleaner having the same

ABSTRACT

A wet-cloth brush for a vacuum cleaner, which generates minor vibration and enables a user to check the operation of a wet-cloth board, comprises a brush body, a fan mounted to the brush body to be rotated by drawn-in air, an eccentric cam mounted to the brush body and operated in association with a power transmitter that transmits a rotational power of the fan, and at least two wet-cloth boards separably mounted to the brush body to move along a locus of the eccentric cam.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit under 35 U.S.C. § 119(a) of Korean Patent Application No. 2004-110043, filed Dec. 22, 2004, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a brush for a vacuum cleaner. More particularly, the present invention relates to a wet-cloth brush for a vacuum cleaner, embodied by attaching a wet-cloth to a brush.

2. Description of the Related Art

When cleaning a place such as a room, it is general to use a vacuum cleaner first to remove dust and impurities and then use a wet cloth to wipe down. However, since such a two-step cleaning work is inconvenient for a user, a wet-cloth brush for a vacuum cleaner, which enables vacuuming and wiping simultaneously, has been introduced and spread.

FIG. 1 illustrates a conventional wet-cloth brush of a vacuum cleaner.

Referring to FIG. 1, the conventional wet-cloth brush 1 for a vacuum cleaner comprises a brush body 10, a fan 20, a power transmitter 30, and a wet-cloth board 40.

The brush body 10 has an air inducing path 11 for drawing in dust-laden air by a suction force generated in a cleaner body (not shown). The fan 20 is mounted on the air inducing path 11 of the brush body 10 to be rotated by the dust-laden air which is drawn in. A pinion gear 21 is mounted under the fan 20 to rotate in association with the fan 20. The power transmitter 30 comprises a pulley gear 31, first and second belts 35 and 37, a first pulley 36 and a second pulley (not shown).

The pulley gear 31 comprises a gear part 32 meshed with the pinion gear 21 and first and second pulley parts 33 and 34 formed on both sides of the gear part 32. The first pulley 36 and the second pulley (not shown) are rotatably mounted to the brush body 10 and have a protrusion (not shown) at a certain distance from a rotational center thereof, respectively. At an upper part of the wet-cloth board 40, recesses (not shown) are formed for insertion of the protrusions of the first pulley 36 and the second pulley.

The above-structured wet-cloth brush 1 operates as follows. When the dust-laden air is drawn in by the suction force, the fan 20 mounted on the air inducing path 11 is rotated. By rotation of the fan 20, the pinion gear 21 disposed under the fan 20 is rotated. Therefore, the gear part 32 of the pulley gear 31 in mesh with the pinion gear 21 is rotated. When the pulley gear 31 rotates according to rotation of the gear part 32, the first pulley 36 and the second pulley are rotated, which are connected with the first and the second pulley parts 33 and 34 of the pulley gear 31 through the first and the second belts 35 and 37. Accordingly, the protrusions of the first pulley 36 and the second pulley crank, and consequently, the wet-cloth board 40 engaged with the protrusions of the first and the second pulleys 36 crank. As a result, the wet-cloth attached to a lower surface of the wet-cloth board 40 wipes away a surface being cleaned, such as a floor.

In the conventional wet-cloth brush 1, however, the wet-cloth board 40 reciprocates very fast, and such a fast motion increases noise and vibration. The vibration is transmitted up to a handle through an extension pipe 3 of the vacuum cleaner, thereby making the user uncomfortable.

In addition, since the wet-cloth board 40 is not obviously seen during the operation, the user cannot instantly recognize whether the wet-cloth is working right.

SUMMARY OF THE INVENTION

An aspect of the present invention is to solve at least the above problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present invention is to provide a wet-cloth brush for a vacuum cleaner, capable of reducing noise and vibration by decreasing a motional speed of a wet-cloth board and by providing a plurality of wet-cloth boards that symmetrically operate, and a vacuum cleaner having the same.

Another aspect of the present invention is to provide a wet-cloth brush for a vacuum cleaner, enabling a user to instantly check the performance of the wet-cloth brush by making the wet-cloth in operation seen from above the wet-cloth brush, and a vacuum cleaner having the same.

In order to achieve the above-described aspects of the present invention, there is provided a wet-cloth brush for a vacuum cleaner, comprising a brush body, a fan mounted to the brush body to be rotated by drawn-in air, a plurality of eccentric cams mounted to the brush body and operated in association with a power transmitter that transmits a rotational power of the fan, and at least two wet-cloth boards separably mounted to the brush body to move along a locus of the eccentric cam.

The power transmitter comprises a plurality of worms mounted to rotation shafts protruded from opposite sides of the fan; and a plurality of worm wheels meshing with the worms having the eccentric cam at a lower end thereof, respectively.

The worm wheels formed at both sides of the fan are rotated in the opposite directions other.

The wet-cloth boards comprises a cam groove formed as a long groove for insertion of the eccentric cam; and a guide projection formed at one side of the cam groove and inserted in a guide formed as a long groove on the brush body.

The two wet-cloth boards repeatedly and linearly move so as to gather at a center part of the brush body and separate from each other.

The two wet-cloth boards respectively have a sloping edge on the sides facing each other.

The wet-cloth boards are mounted to a lower part of the brush body to partly protrude from brush body.

According to another aspect of the present invention, there is provided a vacuum performing wet-cleaning by drawing in dust-laden air through a wet-cloth brush, wherein cloth brush comprises a brush body; a fan mounted to the brush body to be rotated by the drawn-in air; first and second worms respectively mounted to rotation shafts formed on both sides of the fan; first and second worm wheels mounted in the brush body to mesh with the first and the second worms; first and second eccentric cams respectively mounted at a lower part of the first and the second worm wheels and deviated from rotational centers of the worm wheels; and first and second wet-cloth boards including a cam groove formed as a long groove for insertion of anyone of the first and the second eccentric cams, and a guide projection formed at one side of the cam groove and inserted in a guide groove formed as a long groove in the brush body.

The first and the second wet-cloth boards repeatedly and linearly move so as to gather at a center part of the brush body and separate from each other.

The first and the second wet-cloth boards respectively have a sloping edge on the sides facing each other.

The first and the second wet-cloth boards are mounted to a lower part of the brush body to partly protrude from the brush body.

According to the above described wet-cloth brush of a vacuum cleaner, the noise and vibration during the cleaning work can be reduced because the two wet-cloth board reciprocates oppositely to each other at a low speed.

Furthermore, in the wet-cloth brush according to an embodiment of the present invention, the user can instantly recognize the operation of the wet-cloth because the wet-cloth boards are seen from above the wet-cloth brush.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

The above aspect and other features of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawing figures, wherein;

FIG. 1 is a perspective view showing an example of a conventional wet-cloth brush for a vacuum cleaner;

FIG. 2 is a perspective view of a wet-cloth brush for a vacuum cleaner according to an embodiment of the present invention;

FIG. 3 is a bottom view of the wet-cloth brush of FIG. 2;

FIG. 4 is a partial, perspective view of the wet-cloth brush according to an embodiment of the present invention, for explaining the power transmission structure;

FIG. 5 is an exploded, perspective view showing an eccentric cam, a guide groove and a cam groove of the wet-cloth brush according to an embodiment of the present invention;

FIG. 6 is a view for illustrating an assembly structure of first and second eccentric cams of the wet-cloth brush according to an embodiment of the present invention;

FIG. 7 is a view showing an exemplary wet-cloth board of the wet-cloth brush according to an embodiment of the present invention;

FIGS. 8A to 8C are views for illustrating a reciprocating motion of two wet-cloth boards of a wet-cloth brush according to an embodiment of the present invention; and

FIG. 9 is a perspective view of a vacuum cleaner comprising the wet-cloth brush according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Hereinafter, certain embodiments of the present invention will be described in detail with reference to the accompanying drawing figures.

In the following description, same drawing reference numerals are used for the same elements even in different drawings. The matters defined in the description such as a detailed construction and elements are nothing but the ones provided to assist in a comprehensive understanding of the invention. Thus, it is apparent that the present invention can be carried out without those defined matters. Also, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

Referring to FIGS. 2 to 4, a wet-cloth brush 100 for a vacuum cleaner comprises a brush body 110, a fan 120, a power transmitter 130, eccentric cams 141 and 142, and wet-cloth boards 151 and 152.

The brush body 110 is detachably mounted to a pipe 221 of an extension pipe. The brush body 110 has an air inducing path 112 along which a dust-laden air, being drawn in through an air inlet 111 disposed at a lower part thereof, flows toward the pipe 221. A cover (not shown) is attached at an upper part of the brush body 110, thereby shielding the fan 120 and the power transmitter 130 and forming the air inducing path 112.

The fan 120 comprises a blade part 121, and first and second rotation shafts 122 and 123 projected from rotational centers of opposite ends of the blade part 121. The fan 120 is rotatably mounted in the air inducing path 112 of the brush body 110 by the first and the second rotation shafts 122 and 123. The first and the second rotation shafts 122 and 123 are supported by ball bearings 124 and 125, respectively.

The power transmitter 130 consists of a worm and a worm wheel having a significant reduction gear ratio. The wet-cloth brush 100 of the present embodiment comprises first and second power transmitters 131 and 132 to transmit power of the first and the second rotation shafts 122 and 123 of the fan 120. The first power transmitter 131 comprises a first worm 133 mounted to the first rotation shaft 122 of the fan 120 and a first worm wheel 134 meshed with the first worm 133 and rotated parallel with respect to the brush body 110. The second power transmitter 132 is disposed to correspond to the first power transmitter 131 with respect to the fan 120. The second power transmitter 132 comprises a second worm 135 mounted to the second rotation shaft 123 and a second worm wheel 136 meshed with the second worm 135 and rotated parallel with respect to the brush body 110. The first and the second worm wheels 134 and 136 are rotatably supported by first and second rotation supporting members 114 and 116 such as bearing and bush mounted to the brush body 110. The first worm and worm wheel 133 and 134 and the second worm and worm wheel 135 and 136 may be applied by a worm and a worm wheel rotating in the same direction. More specifically, the first worm and worm wheel 133 and 134 and the second worm and worm wheel 135 and 136 may rotate all to the right. However, in order to reduce noise generated by the reciprocating motion of the wet-cloth boards 151 and 152, it is preferable that the first worm and worm wheel 133 and 134 rotate in the opposite direction to the second worm and worm wheel 135 and 136. For example, the first worm and worm wheel 133 and 134 may rotate to the right whereas the second worm and worm wheel 135 and 136 rotate to the left. According to this structure, as the fan 120 operates, the first and the second worm wheel 134 and 136 are rotated in the opposite directions.

Referring to FIGS. 5 and 6, the eccentric cams 141 and 142 are disposed under the worm wheels 134 and 136 to convert a rotational motion of the worm wheels 134 and 136 to a straight motion, in cooperation with the cam grooves 153 and 156 formed in the wet-cloth boards 151 and 152. The eccentric cams 141 and 142 are configured as a pin formed at a predetermined distance ‘e’ from rotational centers of worm wheel shafts 134 a and 136 a. In this embodiment, the first and the second eccentric cams 141 and 142 of a pin shape are disposed under the first and the second worm wheels 134 and 136, respectively.

The wet-cloth boards 151 and 152 are mounted at a lower part of the brush body 100 and respectively have the cam grooves 153 and 156 for insertion of the eccentric cams 141 and 142. The cam grooves 153 and 156 have a certain width for smooth insertion of the eccentric cams 141 and 142 and a certain length by which the eccentric cams 141 and 142 move. That is, the length of the cam grooves 153 and 156 determines a reciprocating distance of the wet-cloth boards 151 and 152. Each of the cam grooves 153 and 156 of the wet-cloth boards 151 and 152 has guide projections 154 and 157 at one side thereof. The guide projections 154 and 157 are inserted in a guide groove 115 to restrict a movement of the wet-cloth boards 151 and 152. The guide groove 115 is configured as a long groove formed at one side of the rotation supporting members 114 and 116, which support the worm wheels 134 and 136, on the brush body 110. For more stable movement of the wet-cloth boards 151 and 152, a pair of the guide grooves 115 are preferably disposed on both sides of the rotation supporting members 114 and 116, respectively. The movement of the wet-cloth boards 151 and 152 is determined by relationships between the cam grooves 153 and 156 and the guide grooves 115 formed on the brush body 110. According to the wet-cloth brush 100 of the present embodiment, as shown in FIG. 5, the cam grooves 153 and 156 of the wet-cloth boards 151 and 152 are disposed perpendicularly to the rotation shafts 122 and 123 of the fan 120 whereas the guide grooves 115 of the brush body 110 are disposed parallel with the rotation shafts 122 and 123 of the fan 120, with respect to a length direction of the grooves. That is, the cam grooves 153 and 156 of the wet-cloth boards 151 and 152 are perpendicularly disposed to the guide grooves 115 of the brush body 110 with respect to the length directions of the grooves. Also, the wet-cloth brush 100 comprises a pair of the guide grooves 115 on both sides of the first and the second rotation supporting members 114 and 116 that support the first and the second worm wheels 134 and 136 of the brush body 110, respectively, and a pair of the guide projections 154 and 157 on the wet-cloth boards 151 and 152 to correspond to the guide grooves 115. The guide projections 154 and 157 have at an upper part thereof escape-prevention members 155 and 158 fixed by a fastening member such as a bolt, respectively, to restrain the wet-cloth boards 151 and 152 from escaping from the guide grooves 115 of the brush body 110. A plain washer having a diameter greater than a width of the guide groove 115 may be used for the escape-prevention members 155 and 158. Therefore, as the eccentric cams 141 and 142 are rotated by the worm wheels 134 and 136, the wet-cloth boards 151 and 152 can linearly reciprocate through the cam grooves 153 and 156 inserted with the eccentric cams 141 and 142 and the guide projections 154 and 157 inserted in the guide grooves 115, without being separated from the brush body 110. On the other side of the wet-cloth boards 151 and 152, which is opposite to a side where the cam grooves 153 and 156 and the guide projections 154 and 157 are formed, a plurality of sticking seats 159 (FIG. 3), such as velcro tape, are provided to attach the wet-cloth (not shown).

Although the first and the second wet-cloth boards 151 and 152 may be operated by the first and the second eccentric cams 141 and 142 independently, it is preferable that they are operated in association with each other. In order for reduction of the vibration, the wet-cloth boards 151 and 152 may be symmetrically operated. For example, if the first wet-cloth board 151 moves toward a center part of the brush body 110, the second wet-cloth board 152 moves toward the center part, and if the first wet-cloth board 151 moves outward with respect to the brush body 110, so does the second wet-cloth board 152. In other words, the first and the second wet-cloth boards 151 and 152 reciprocate in motions of gathering at the center part of the brush body 110 and separating to outer parts of the brush body 110. To this end, the first and the second worm wheels 134 and 136 are rotated in the opposite directions to each other. The first and the second eccentric cams 141 and 142 are disposed in the same direction, as shown in FIG. 6.

However, in the above-operated wet-cloth brush 100, a finger or any other stuff may be pinched by the first and the second wet-cloth boards 151 and 152 gathering to the center part. To prevent this, the first and the second wet-cloth boards 151 and 152 preferably have sloping edges 151 a and 152 a facing each other, respectively. In greater detail, the sloping edges 151 a and 152 a are formed by sharpening the wet-cloth boards 151 and 152 from bottom surfaces 151 c and 152 c directly attached with the wet-cloth toward upper surfaces 151 d and 152 d directly mounted to the brush body 110.

Furthermore, the wet-cloth boards 151 and 152 have a certain size for allowing the wet-cloth boards 151 and 152 to be partly exposed and shown by a user from above the brush body 110. Therefore, the user can check the operation of the wet-cloth boards 151 and 152 while operating the vacuum cleaner. In this embodiment, both comers 113 of a side of the brush body 110, the side connected to the pipe 221, are rounded while the first and the second wet-cloth boards 151 and 152 are substantially formed as a rectangle. Accordingly, one corner of the respective wet-cloth boards 151 and 152 can always be shown through the rounded comers 113 of the brush body 100. Additionally, it is preferable that flank sides 151 b and 152 b of the wet-cloth boards 151 and 152 are shown, protruding from the brush body 110, when the both wet-cloth boards 151 and 152 are moved to the outermost limit, as shown in FIG. 8.

Hereinbelow, the operation of the wet-cloth brush for a vacuum cleaner will be described in reference to FIGS. 2 thorugh 8.

When a suction force is generated by a motor mounted in a cleaner body (not shown), dust-laden air is drawn in through the air inlet 111 formed in the brush body 110. While passing through the air inducing path 112, the drawn-in air rotates the fan 120 which is supported on the air inducing path 112 with both sides thereof by the ball bearings 124 and 125. As the fan 120 rotates, the first and the second worms 133 and 135 mounted to the rotation shafts 122 and 123 are integrally rotated. Accordingly, the first and the second worm wheels 134 and 136 in mesh with the first and the second worms 133 and 135 are rotated. Thereby, the first and the second eccentric cams 141 and 142 integrally formed with a lower part of the worm wheels 134 and 136 are rotated at a certain distance from the rotational centers of the first and the second worm wheels 134 and 136, as shown in FIG. 6. Because the first worm and worm wheel 133 and 134 and the second worm and worm wheel 135 and 136 rotate in the opposite directions to each other, if the first worm wheel 134 rotates clockwise, for example, the second worm wheel 136 rotates counterclockwise.

As the first and the second eccentric cams 141 and 142 rotate, the first and the second wet-cloth boards 151 and 152 linearly reciprocate in a length direction of the brush body 110 by the cam grooves 153 and 156 inserted with the first and the second eccentric cams 141 and 142 and the guide projections 154 and 157 inserted in the guide grooves 115 of the brush body 110. Here, since the first and the second eccentric cams 141 and 142 are symmetrically disposed and rotated in the opposite directions, as shown in FIG. 6, the first and the second wet-cloth boards 151 and 152 also symmetrically reciprocate by rotation of the fan 120.

FIGS. 8A to 8C show the operation of the first and the second wet-cloth boards 151 and 152. More specifically, FIG. 8A shows the first and the second wet-cloth boards 151 and 152 as moved to the outermost limit by rotation of the first and the second eccentric cams 141 and 142. FIG. 8B shows the wet-cloth boards 151 and 152 being gathering toward the center part of the brush body 110, and FIG. 8C show the wet-cloth boards 151 and 152 as moved to the center part of the brush body 110 as much as possible. By the symmetrical movement of the first and the second wet-cloth boards 151 and 152 as the above, the vibration generated by the reciprocating motion of the wet-cloth boards 151 and 152 can be decreased and prevented from being transmitted up to the handle 222 (FIG. 9) through the pipe 221.

In addition, as shown in FIG. 8A, the flank side 151 b and 152 b of the wet-cloth boards 151 and 152 are partly protruded from the brush body 110 when the wet-cloth boards 151 and 152 are moved to the outermost limit. Therefore, the user can easily check the operation of the wet-cloth boards 151 and 152.

Moreover, the first and the second wet-cloth boards 151 and 152 respectively have sloping sides 151 a and 152 a facing each other, as shown in FIG. 7. Therefore, a finger or other stuff is not pinched by the wet-cloth boards 151 and 152 although the wet-cloth boards 151 and 152 are moved to the center part.

FIG. 9 shows the operation of a vacuum cleaner applying the wet-cloth brush 100 according to an embodiment of the present invention.

Referring to FIG. 9, a vacuum cleaner 200 according to an embodiment of the present invention, comprises a wet-cloth brush 110 for drawing in dust-laden air, the extension pipe 220 fluidly connecting the wet-cloth brush 100 with a cleaner body 230, and the cleaner body 230 including a dust collecting chamber 235 and a motor chamber 231.

Referring to FIGS. 2 and 3, the wet-cloth brush 100 comprises the brush body 110 having the air inlet 111 for drawing in dust-laden air from a surface being cleaned, and a pair of wet-cloth boards 151 and 152 linearly reciprocating with respect to the brush body 110. Since the structure of the wet-cloth brush 100 has been described above, detailed description thereof will be omitted. The extension pipe 220 comprises a pipe 221 removably attached with the wet-cloth brush 100, the handle 222 for moving the wet-cloth brush 100, and a flexible hose 223 fluidly connecting the handle 222 and the cleaner body 230. The dust collecting chamber 235 includes a contaminant collecting unit (not shown) for separating and collecting dust from the dust-laden air drawn in through the wet-cloth brush 100. The contaminant collecting unit may be implemented by any of a general dust bag and a cyclone dust collecting unit. The motor chamber 231 has a motor assembly 210 for generating the suction force for drawing in the dust-laden air through the wet-cloth brush 100. The motor assembly 210 comprises a motor 211, an impeller (not shown) rotated by the motor 211, and a diffuser 212 for inducing the air drawn in by the impeller to the motor 211.

When cleaning a place using the vacuum cleaner 200 according to an embodiment of the present invention, a power switch is turned on to rotate the motor 211 in the motor chamber 231. As the motor 211 rotates, the impeller mounted to a leading end of a motor shaft is rotated. By this, the dust-laden air is drawn in through the air inlet 111 of the wet-cloth brush 100.

The drawn-in air flows along the air inducing path 112 in the brush body 100, thereby rotating the fan 120. According to rotation of the fan 120, the pair of wet-cloth boards 151 and 152 are symmetrically operated by the eccentric cams 141 and 142, the cam grooves 153 and 156, the guide grooves 115 and the guide projections 154 and 157 to linearly reciprocate (See FIG. 4). As a result, the surface being cleaned such as floor can be thoroughly wiped away by the wet-cloth (not shown) attached to the bottom surfaces 151 c and 152 c of the wet-cloth boards 151 and 152. During this, the user holding the handle 222 can view each of the one corner of the wet-cloth boards 151 and 152 from above the brush body 110. In addition, since the flank sides 151 b and 152 b are partly protruded from the brush body 110 when the wet-cloth boards 151 and 152 are moved to the outermost limit, the user can confirm whether the cleaning work is being performed right. While passing through the contaminant collecting unit of the dust collecting chamber 235, the dust-laden air passed through the fan 120 is cleaned since the dust is separated therefrom. The cleaned air is passed through the motor 211 via the impeller and the diffuser 212 and discharged to the outside of the cleaner body 230 through an outlet 233.

While the invention has been shown and described with reference to certain embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. 

1. A wet-cloth brush for a vacuum cleaner, comprising: a brush body; a fan mounted to the brush body to be rotated by drawn-in air; a plurality of eccentric cams mounted to the brush body and operated in association with a power transmitter that transmits a rotational power of the fan; and at least two wet-cloth boards mounted to the brush body to move along a locus of the eccentric cam.
 2. The wet-cloth brush of claim 1, wherein the power transmitter comprises: a plurality of worms mounted to a rotation shaft protruded from opposite sides of the fan; and a plurality of worm wheels meshing with the worms and having the eccentric cam at a lower end thereof, respectively.
 3. The wet-cloth brush of claim 2, wherein the worm wheels formed at both sides of the fan are rotated in the opposite directions to each other.
 4. The wet-cloth brush of claim 1, wherein the wet-cloth boards comprises: a cam groove formed as a long groove for insertion of the eccentric cam; and a guide projection formed at one side of the cam groove and inserted in a guide groove formed as a long groove on the brush body.
 5. The wet-cloth brush of claim 4, wherein the two wet-cloth boards repeatedly and linearly move so as to gather at a center part of the brush body and separate from each other.
 6. The wet-cloth brush of claim 5, wherein the two wet-cloth boards respectively have a sloping edge on the sides facing each other.
 7. The wet-cloth brush of claim 1, wherein the wet-cloth boards are mounted to a lower part of the brush body to partly protrude from the brush body.
 8. A vacuum cleaner performing wet-cleaning by drawing in dust-laden air through a wet-cloth brush, wherein the wet-cloth brush comprises: a brush body; a fan mounted to the brush body to be rotated by the drawn-in air; first and second worms respectively mounted to rotation shafts formed on both sides of the fan; first and second worm wheels mounted in the brush body to mesh with the first and the second worms; first and second eccentric cams respectively mounted at a lower part of the first and the second worm wheels and deviated from rotational centers of the worm wheels; and first and second wet-cloth boards including a cam groove formed as a long groove for insertion of anyone of the first and the second eccentric cams, and a guide projection formed at one side of the cam groove and inserted in a guide groove formed as a long groove in the brush body.
 9. The vacuum cleaner of claim 8, wherein the first and the second wet-cloth boards repeatedly and linearly move so as to gather at a center part of the brush body and separate from each other.
 10. The vacuum cleaner of claim 8, wherein the first and the second wet-cloth boards respectively have a sloping edge on the sides facing each other.
 11. The vacuum cleaner of claim 8, wherein the first and the second wet-cloth boards are mounted to a lower part of the brush body to partly protrude from the brush body. 